It has been estimated that Sri Satya Sai Baba, India's biggest spiritual leader, has up to 30 million devotees around the world.

But increasing numbers of former followers are alleging he has sexually abused them or their families. This World investigates.

Swamis, otherwise known as yogis or gurus, are the holy men of India, and part of ancient tradition.

Sai Baba, 78, is based in Puttaparthi, near Bangalore in southern India. His distinctive 1960s orange robes and Afro hairstyle make him instantly recognisable.

As the country's biggest "God-man" - a human being who declares himself divine - he professes to be the reincarnation of a Hindu God-man from the 19th Century.

Sai Baba not only commands huge regular audiences at the local ashram (religious retreat) - where he performs countless "miracles" - he also boasts followers from more than 165 countries world-wide.

But as the This World team discovers as they travel from India to California, there are a number of former devotees who have turned away from his teachings, claiming he has ruined their lives.

Alaya, a former follower who claims he was sexually abused by the swami, says in the programme: "I remember him saying, if you don't do what I say, your life will be filled with pain and suffering."

In an intimate and powerful portrait, Alaya's family talks openly about how they feel they were betrayed.

Back in India, there are serious questions to be asked of politicians, who seem to have continuously ignored the problem. Indeed, some would say, the correct position for these politicians appears to be at the feet of Sai Baba.

He certainly has friends in high places, and throughout the scandal, his popularity has remained intact.

Has this "God-man" been wrongly accused or does his status mean he is immune to criticism?